Airport Foldable and Fragile Pole Application Scope: Support structures for all auxiliary navigation equipment within the runway obstruction area limitation surface.
Fragile and brittle items — objects that may break (shatter), bend, or yield under specified impact forces, thereby posing a lesser hazard to aircraft as lightweight objects.
Fragility
Visual and non-visual navigation facilities at airports (such as approach lighting towers, meteorological equipment, and radio navigation equipment, etc.) are generally located near runways, taxiways, and aprons. Failure to prevent accidental collisions with aircraft during takeoff or landing could be dangerous. All such equipment and their supports must be collapsible and installed as low as possible to ensure that collisions do not lead to aircraft control loss. Collapsibility can be achieved through various design concepts, such as using lightweight, brittle, and low-toughness materials, components, and connectors, to ensure that collapsible objects shatter, bend, or yield upon impact.
Flexible and fragile poles (hereinafter referred to as "flexible poles") are support structures made in single-pole, tower frame, and other configurations, utilizing lightweight, fragile materials and a flexible design.
Condition for bending of aviation easily breakable and fragile rods
For aircraft with potential for non-lift or non-glide landing, the breakable rod must bend and break upon impact from an aircraft weighing 3,000 kg and traveling at 140 km/h. For aircraft with potential for non-ground sliding, the breakable rod must bend and break upon impact from an aircraft weighing 3,000 kg and traveling at 50 km/h. The force exerted by the breakable rod on the aircraft during impact should not exceed 45 KN; the energy transferred to the aircraft by the breakable rod should not exceed 55 KJ.